Start by clarifying the goal: full coverage means every public road in San Francisco captured at Street View quality. Break the problem into estimating total road miles, the daily coverage rate per driver, and the time frame, then compute the number of drivers needed. State assumptions explicitly and show how changes in assumptions affect the result.
Pro tip: Acknowledge that this is a Fermi estimation problem and that the exact number matters less than your structured reasoning; mention that in reality Google uses a mix of drivers, third-party contractors, and crowd-sourced imagery, so the answer is a planning estimate.
Define what 'full coverage' means: all public roads, one pass per road, during daylight and good weather. State assumptions about SF's road network size and driver productivity.
Use known data: San Francisco has about 1,000 miles of public roads (or estimate from area and density). Include both directions if needed, but typically one pass per road segment suffices.
Assume a driver can cover 20-30 miles per day at an average speed of 10-15 mph, accounting for stops, traffic, and setup. This yields a daily coverage rate.
Decide on a target completion time (e.g., 1 month, 3 months). Divide total road miles by (daily rate × working days) to get the number of drivers.
Validate the result against intuition (e.g., a handful of drivers for a few months). Discuss factors like cost, coordination, and alternative methods (e.g., crowd-sourcing).
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.